Power System Protection MCQs Part 15
Contents
Bulk oil circuit breaker is generally suitable for voltage levels up to
Bulk oil circuit breaker is generally suitable for voltage levels up to
- 3.3 kV
- 11 kV
- 13.5 kV
- 66 kV
Correct answer: 4. 66 kV
Explanation: Bulk oil circuit breakers employ large quantity of oil. Oil in these breakers serves two purposes. Firstly, it extinguishes the arc during opening of contacts. Alongside this, it insulates the current-conducting parts from one another and from the earthed tank. Generally bulk oil circuit breakers are recommended for voltage levels up to 66 kV. For higher voltage levels low oil circuit breakers are recommended. For very high volage levels SF6 circuit breakers are recommended.
High speed circuit breakers can complete their operation in
High speed circuit breakers can complete their operation in
- 1 to 3 cycles
- 6 to 12 cycles
- 3 to 8 cycles
- 8 to 36 cycles
Correct answer: 3. 3 to 8 cycles
Lightning arrestor should be installed
Lightning arrestor should be installed
- In close proximity to the circuit breaker
- Away from the transformer
- Near the transformer
- Away from the circuit breaker
Correct answer: 3. Near the transformer
Reactance relay is generally preferred for protection against
Reactance relay is generally preferred for protection against
- Earth faults only
- Phase faults only
- None of these
Correct answer: 1. Earth faults only
Percent bias for a generator protection lies between
Percent bias for a generator protection lies between
- 5 to 10
- 10 to 20
- 20 to 25
- None of these
Correct answer: 1. 5 to 10